In recent years, with an increase in the screen size of a display, an increase in the size of a substrate for the display has been promoted. Carrying such a large-sized substrate in a conventional horizontal system is faced with various problems.
For example, due to an increase in the size of, and a reduction in the thickness of, the substrate, the horizontally mounted substrate tends to bend and warp under its own weight, which makes accurate film-formation in terms of film thickness and flatness difficult. Further, the film-forming apparatus structure is increased in size corresponding to the area of the substrate, which causes a need for obtaining a considerable occupied space.
On the other hand, a vertical carrying system which supports one side of a substrate by a carrier and carries the substrate in a nearly upright state is also proposed (see the following Patent Documents 1 and 2, for example). By this vertical carrying system, bending and warpage of the substrate are prevented, whereby the increase in the size of the substrate can be addressed. Further, there is an advantage that the occupied space of a substrate transfer apparatus can be reduced.
Patent Document 1: Patent Publication No. 2948842
Patent Document 2: Japanese Patent Application Laid-open No. 2004-83997